feat(auth): extend API key authentication to tRPC endpoints (#4732)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

packages/api/src/open-api.ts

@@ -1,5 +1,7 @@
 import { generateOpenApiDocument } from "trpc-to-openapi";
 
+import { API_KEY_HEADER_NAME } from "@homarr/auth/api-key";
+
 import { appRouter } from "./root";
 
 export const openApiDocument = (base: string) =>
@@ -11,7 +13,7 @@ export const openApiDocument = (base: string) =>
     securitySchemes: {
       apikey: {
         type: "apiKey",
-        name: "ApiKey",
+        name: API_KEY_HEADER_NAME,
         description: "API key which can be obtained in the Homarr administration dashboard",
         in: "header",
       },